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Notes  on  a  Recent  Study 

OF  THE  . 

Atlantic  City  Steel  Paint  Tests 


SCIENTIFIC  SECTION 

HENRY  A.  GARDNER,  Director 


Educational  Bureau 

Paint  M’f’rs  Association  of  the  United  States 
Philadelphia,  Pa. 


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BULLETIN  32 


Notes  on  a  Recent  Study 

OF  THE 

Atlantic  City  Steel  Paint  Tests 


SCIENTIFIC  SECTION 

HENRY  A.  GARDNER,  Director 


Educational  Bureau 

Paint  M’f’rs  Association  of  the  United  States 
Philadelphia,  Pa. 


Distributed  by 
G.  B.  H ECKEL,  Secretary 
636  Bourse  Bldg..  Philadelphia,  Pa. 


Copyright.  1912,  by 
H.  A.  GARDNER 


THE  GETTY  RESfiAftCti 
INSTITUTE  LIBRMiy 


NOTES  ON  A  RECENT  STUDY 
OF  THE  ATLANTIC  CITY  STEEL  PAINT  TESTS 


By  Henry  A.  Gardner, 

Assistant  Director,  Institute  of  Industrial  Research,  Washington,  D.  C. 


A  recent  inspection  of  the  painted  steel  test 
panels*  erected  by  the  Paint  Manufacturers’  As¬ 
sociation  at  Atlantic  City  during  October,  1908r 
lias  disclosed  some  startling  changes  in  the 
weathering  of  the  various  paints  as  compared 
to  their  condition  a  year  ago.  These  tests,  which 
include  a  great  number  of  oil  paints,  are  af¬ 
fording  most  important  information  as  to  the 
comparative  value  of  various  pigments,  when 
ground  in  linseed  oil,  as  protective  coatings  for 
ferrous  metals.  Several  of  the  paints  have  given 
excellent  results,  while  others  have  completely 
failed  to  serve  their  intended  purpose.  The 
original  contention  upon  which  the  tests  were 
based,  that  pigments  of  the  rust  inhibitive  and 
inert  types,  such  as  the  slightly  soluble  chromates, 
the  basic  compounds,  and  the  metallic  oxides, 
would  prove  superior  to  those  pigments  of  the 
tentatively  termed  rust  stimulative  class,  which 
induce  electrolysis  either  through  the  effect  of 

*  Bulletin  27.  Paint  Mfrs.  Asso.  of  tlie  U.  S.  “Corrosion  of  Iron  and 
Steel.”  Cuslnnan  and  Gardner:  McGraw-IIill  Book  Co.,  X.  Y. 


contained  acid  impurities  or  through  their  electro¬ 
negative  nature,  has  been  fully  justified. 

While  some  single-pigment  paints  have  failed  in 
certain  respects,  it  is  by  no  means  certain  that 
these  paints  would  act  in  the  same  way  under  con¬ 
ditions  of  actual  practice  where  they  would  be  used 
in  combination  with  other  pigments  which  might 
tend  to  overcome  their  inherent  defects.  This 
statement  would  apply  especially  to  pigments  of 
the  inert  class,  such,  for  instance,  as  barytes 
or  whiting.  These  pigments  are  never  used 
alone  in  paints.  They  are  always  combined 
with  some  of  the  more  opaque  pigments  in  order 
that  their  defects  may  be  corrected,  sometimes 
lending  in  turn  a  strengthening  effect  to  the  pig¬ 
ments  with  which  they  are  combined.  This  point 
is  well  illustrated  in  tests  Nos.  19  and  21,  in  which 
the  pigment  Barytes  seems  to  have  had  the  effect 
of  prolonging  the  life  of  the  black  carbon  pig¬ 
ments  with  which  it  was  combined. 

Panel  No.  1,  painted  with  Old  Dutch  Process 
White  Lead  (Basic  Carbonate-White  Lead),  and 
Panel  No.  2,  painted  with  Quick  Process  White 
Lead  (Basic  Carbonate-White  Lead),  are  both  in 
very  poor  condition,  their  surfaces  being  covered 
with  rust  streaks  which  appear  wherever  brush 
marks  were  shown  at  the  initial  painting.  Early 
in  the  test  these  panels  developed  considerable 
chalking,  which  was  progressively  washed  off 
to  such  an  extent  that  in  the  summer  of  1911 


4 


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a  very  tliin  coating  was  left.  This  coating  dur¬ 
ing  the  past  year  has  failed  in  a  great  many  places, 
scaling  and  marked  signs  of  disintegration  having- 
appeared. 

Panel  No.  3,  painted  with  Zinc  Oxide,  indicated 
at  the  beginning  of  the  test  that  the  paint  used  was 
too  stiff  and  thus  lacking  in  elasticity;  Zinc  Oxide 
being  a  pigment  which  demands  a  considerable 
quantity  of  oil.  The  rust  lines  on  the  paint,  where 
the  brush  marks  were  left,  are  heavy.  What  re¬ 
mains  of  the  paint,  however,  is  very  hard,  and  be¬ 
neath  the  surface  the  steel  is  clean,  indicating  that 
the  pigment  itself  is  of  an  inliibitive  nature. 

Panel  No.  4,  painted  with  Basic  Sulphate- White 
Lead,  and  Panel  No.  5,  painted  with  Sublimed 
Blue  Lead,  are  both  in  excellent  condition.  Al¬ 
though  considerable  chalking  was  shown  on  each 
of  these  panels,  the  paint  films  are  intact  and  of  a 
tough,  elastic  nature,  presenting  to  the  touch  a 
velvety  feeling.  The  Sublimed  Blue  Lead  was 
somewhat  superior  to  the  Basic  Sulphate- White 
Lead,  although  the  latter  showed  better  color 
maintenance. 

Panel  No.  6,  painted  with  Litliopone,  indicated 
at  the  beginning  of  the  test  that  this  pigment  when 
used  alone  was  unfit  for  the  protection  of  iron  and 
steel  exposed  to  the  weather.  The  panel  at  the 
present  time  is  covered  with  rust  beneath  the  sur¬ 
face  of  the  film,  and  in  some  places  the  rust  has 
broken  through  and  disrupted  the  coating.  The 


coating  is  very  dark  in  appearance,  having  fogged 
considerably  through  the  action  of  light. 

Panel  No.  7,  painted  with  Zinc  Lead,  is  streaked 
with  dark  brown  rust  wherever  the  brush  marks 
were  formerly  apparent. 

At  the  beginning  of  the  test  Panel  No.  9,  painted 
with  American  Orange  Mineral,  and  Panel  No. 
10,  painted  with  Red  Lead,  gave  excellent  service. 
Until  last  year  these  panels  were  in  perfect  con¬ 
dition  except  for  a  whitening  of  the  surface  which 
is  probably  due  to  the  formation  of  a  coating  of 
white  carbonate  of  lead,  effected  by  the  carbonic 
acid  of  the  atmosphere,  giving  to  the  panels  a  pink¬ 
ish  tint.  On  panel  No.  9  there  are  several  slight 
rust  spots  appearing  through  the  surface  of  the 
paint.  Panel  No.  10  is  slightly  darker  than  Panel 
No.  9,  and  has  offered  greater  resistance  to  the  de¬ 
structive  effect  of  the  salt  air. 

Panel  No.  12,  painted  with  Bright  Red  Oxide, 
and  Panel  No.  14,  painted  with  Venetian  Red,  are 
both  in  generally  good  condition,  with  the  excep¬ 
tion  of  a  few  rusty  brush  streaks  on  Panel  No.  12 
and  a  few  slight  corrosion  spots  on  Panel  No.  14. 

Panel  No.  15,  painted  with  Metallic  Brown 
Oxide,  is  also  giving  very  good  service  except 
for  the  appearance  on  the  paint  film  of  several 
eruptions  of  pin-head  size,  which  have  apparently 
not  broken  through  but  which  have  lifted  the 
paint  coating  slightly  in  spots. 

Panel  No.  16,  painted  with  Natural  Graphite, 

6 


shows  several  slight  pin-head  eruptions  on  the  sur¬ 
face,  as  well  as  several  deep  corrosion  spots  spread 
about.  Its  surface  is  chalking  considerably. 

Panel  No.  17,  painted  with  Artificial  Graphite, 
is  uniformly  covered  with  large  rust  spots,  which 
are  spreading  over  a  wide  area,  and  thousands  of 
small  pin-liead  eruptions.  This  panel  is  chalking 
heavily,  the  chalked  surface  resembling  stove 
polish  in  appearance.  The  inferior  condition  of 
this  panel  as  compared  with  Panel  No.  16  (Nat¬ 
ural  Graphite)  may  be  accounted  for  by  the  fact 
that  Natural  Graphite  contains  inert  pigments 
such  as  silica  and  iron  oxide. 

Panel  No.  19,  painted  with  Lampblack  and 
Barytes,  is  covered  with  small  round  pin-head 
eruptions  which  have  not  yet  broken  through.  It 
also  has  a  spotted  and  dull  appearance  and  shows 
considerable  chalking. 

Panel  No.  20,  painted  with  Willow  Charcoal,  is 
the  best  appearing  black  of  carbonaceous  origin 
upon  the  fence.  It  has  a  deep  color  and  is  show¬ 
ing  no  corrosion  nor  chalking. 

On  Panel  No.  21,  painted  with  Gas  Carbon 
Black  and  Barytes,  there  is  considerable  chalking 
with  a  few  rust  spots  apparent.  This  type  of 
black,  however,  is  superior  in  appearance  to 
No.  19. 

Panel  No.  24,  painted  with  Ochre,  is  covered 
with  many  small  rust  eruptions  as  well  as  several 
very  bad  rust  spots.  The  paint  film  has  become 

7 


brown,  due  to  the  corroded  surface  beneath.  The 
him  itself,  however,  is  intact. 

Panel  No.  27,  painted  with  Natural  Barytes, 
has  scaled,  and  the  paint  that  is  left  upon  the  sur¬ 
face  is  badly  discolored  with  rust. 

Panel  No.  28,  painted  with  Precipitated  Barium 
Sulphate  or  Blanc  Fixe,  is  also  scaling,  and  the 
portion  of  the  film  that  is  intact  is  pin-holed, 
stained,  and  streaked. 

Panels  Nos.  29  and  30,  painted  respectively  with 
Calcium  Carbonate  and  Precipitated  Calcium  Car¬ 
bonate,  are  covered  with  rust,  no  pigment  being- 
left  upon  the  plates.  At  the  start  of  the  test  these 
panels  chalked  to  such  an  extent  that  the  chalked 
surface  was  washed  off  by  the  rains  before  the 
test  had  weathered  two  years. 

Panel  No.  31,  painted  with  Gypsum,  is  of  a  dark 
brown  color  and  is  showing  several  rusty  streaks. 
Its  surface  is  entirely  covered  with  small  pin-head 
eruptions. 

Panel  No.  32,  painted  with  China  Clay,  is  fairly 
white,  and  although  there  are  a  few  rust  streaks 
appearing,  it  is  in  fair  condition. 

Panel  No.  33,  painted  with  Asbestine,  is  in 
similar  condition  to  Panel  No.  32,  the  rust  streaks 
being  slightly  more  pronounced. 

Panel  No.  34,  painted  with  American  Vermilion 
(Basic  Chromate  of  Lead),  is  in  perfect  condition. 

Panel  No.  36,  painted  with  Lead  Chromate,  is 
streaked  around  the  edges  for  a  distance  of  six 

8 


inches  with  thin  lateral  and  horizontal  streaks  of 
rust.  The  middle  of  the  panel,  however,  is  in  good 
condition. 

Panel  No.  39,  painted  with  Zinc  Chromate,  is  in 
excellent  condition. 

Panel  No.  40,  painted  with  Zinc-and-Barium 
Chromate,  has  developed  a  slight  greenish  tint  and 
a  little  chalking.  Otherwise  this  panel  is  in  ex¬ 
cellent  condition. 

Panel  No.  41,  painted  with  Pure  Chrome  Green, 
is  in  perfect  condition  except  for  the  development 
of  a  slight  bluish  tint  along  the  edges. 

Panels  Nos.  44  and  45,  painted  with  Prussian 
Blue,  are  both  in  good  condition.  While  Panel 
No.  44  has  developed  a  slight  greenish  tint,  Panel 
No.  45  is  still  evidencing  a  most  brilliant  main¬ 
tenance  of  its  dark  blue  color  and  gloss. 

Panel  No.  48,  painted  with  Ultramarine  Blue, 
is  entirely  covered  with  rust,  the  paint  having 
chalked  off  completely. 

Panel  No.  49,  painted  with  Zinc  and  Lead 
Chromate,  is  in  perfect  condition,  with  the  excep¬ 
tion  of  a  few  slight  rust  spots. 

Panel  No.  51,  painted  with  Precipitated  Black 
Oxide  of  Iron,  is  in  good  condition,  with  the  ex¬ 
ception  of  slight  chalking. 


9 


Photographic  Views  of  Some  of  the 
Panels  on  the  Atlantic  City 
Steel  Test  Fence 


13 


Panel  No.  1  Detail  Panel  No.  2 

Corroded  White  Lead  (Basic  Carbonate-  April,  1912  Corroded  White  Lead  (Basic  Carbonate- 
White  Lead),  Old  Dutch  Process  White  Lead),  Quick  Process 

(Note  how  the  heavy  rust  streaks  follow  the  brush  marks.) 


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April,  1912 

Panel  No.  17  Panel  No.  19  Panel  No.  20 

Artificial  Graphite  Lampblack  and  Baryites  Willow  Charcoal 


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19 


(Note  excellent  condition  of  rust-inliibitive  pigment  paints. ) 


* 


June,  1910 

American  Vermilion  (Basie  Chromate  of  Lead) 

20 


Panel  6666 

Corrosion  pits  on  panel  painted  with  stimulative  pigment 

June,  1910 


21 


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